Expand and Collapse tableview cells

Question

I'm able to expand and collapse cells but i wanna call functions (expand and collapse) inside UITableViewCell to change button title.

import UIKit

class MyTicketsTableViewController: UITableViewController {

    var selectedIndexPath: NSIndexPath?
    var extraHeight: CGFloat = 100

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 5
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! MyTicketsTableViewCell
        return cell
    }

    override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        if(selectedIndexPath != nil && indexPath.compare(selectedIndexPath!) == NSComparisonResult.OrderedSame) {
            return 230 + extraHeight
        }

        return 230.0
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        if(selectedIndexPath == indexPath) {
            selectedIndexPath = nil
        } else {
            selectedIndexPath = indexPath
        }

        tableView.beginUpdates()
        tableView.endUpdates()
    }
}

import UIKit

class MyTicketsTableViewCell: UITableViewCell {

    @IBOutlet weak var expandButton: ExpandButton!
    @IBOutlet weak var detailsHeightConstraint: NSLayoutConstraint!

    var defaultHeight: CGFloat!

    override func awakeFromNib() {
        super.awakeFromNib()

        defaultHeight = detailsHeightConstraint.constant

        expandButton.button.setTitle("TAP FOR DETAILS", forState: .Normal)
        detailsHeightConstraint.constant = 30
    }

    func expand() {
        UIView.animateWithDuration(0.3, delay: 0.0, options: .CurveLinear, animations: {
            self.expandButton.arrowImage.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 0.99))
            self.detailsHeightConstraint.constant = self.defaultHeight
            self.layoutIfNeeded()

            }, completion: { finished in
                self.expandButton.button.setTitle("CLOSE", forState: .Normal)
        })
    }

    func collapse() {
        UIView.animateWithDuration(0.3, delay: 0.0, options: .CurveLinear, animations: {
            self.expandButton.arrowImage.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 0.0))
            self.detailsHeightConstraint.constant = CGFloat(30.0)
            self.layoutIfNeeded()

            }, completion: { finished in
                self.expandButton.button.setTitle("TAP FOR DETAILS", forState: .Normal)
        })
    }

}

Answer 1

If you want the cell to get physically bigger, then where you have your store IndexPath, in heightForRow: use:

override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if selectedIndexPath == indexPath {
      return 230 + extraHeight
    }
    return 230.0
}

Then when you want to expand one in the didSelectRow:

selectedIndexPath = indexPath
tableView.beginUpdates
tableView.endUpdates

Edit

This will make the cells animate themselves getting bigger, you dont need the extra animation blocks in the cell.

Edit 2

 override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        if(selectedIndexPath == indexPath) {
          selectedIndexPath = nil

          if let cell = tableView.cellForRowAtIndexPath(indexPath) as? MyTicketsTableViewCell {
            cell.collapse()
          }
          if let cell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow:indexPath.row+1, section: indexPath.section) as? MyTicketsTableViewCell {
            cell.collapse()
          }
        } else {
          selectedIndexPath = indexPath

          if let cell = tableView.cellForRowAtIndexPath(indexPath) as? MyTicketsTableViewCell {
              cell.expand()
          }

          if let cell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow:indexPath.row+1, section: indexPath.section) as? MyTicketsTableViewCell {
             cell.expand()
          }
        }

        tableView.beginUpdates()
        tableView.endUpdates()
    }

Answer 2

All you need is implement UITableView Delegate this way:

override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

override func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

By default, estimatedHeight is CGRectZero, when you set some value for it, it enables autoresizing (the same situation with UICollectionView), you can do even also so:

tableView?.estimatedRowHeight = CGSizeMake(50.f, 50.f); 

Then you need to setup you constraints inside your cell.

Check this post: https://www.hackingwithswift.com/read/32/2/automatically-resizing-uitableviewcells-with-dynamic-type-and-ns

Hope it helps)

Answer 3

In MyTicketsTableViewController class, inside cellForRowAtIndexPath datasource method add target for the button.

cell.expandButton.addTarget(self, action: "expandorcollapsed:", forControlEvents: UIControlEvents.TouchUpInside)

Answer 4

I tried to implement lots of the given examples on this and other pages with similar questions, but none worked for me since I had to perform some logic in my custom cell (eg. hide unneeded UILables in CustomCell.swift when the cell is collapsed).

Here is the implementation that worked for me:

1. Create a dictionary:

   private var _expandedCells: [IndexPath:Bool] = [:]
   

2. Implement the heightForRowAt method:

   func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
       return _expandedCells[indexPath] == nil ? 70 : _expandedCells[indexPath]! ? 150 : 70
   }
   

3. Implement the didSelectRowAt method:

   func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
   
       _expandedCells[indexPath] = _expandedCells[indexPath] == nil ? true : !_expandedCells[indexPath]!
   
       tableView.reloadRows(at: [indexPath], with: .fade)
   }
   

4. Adjust your customCell:

   func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
   
       guard let cell = cell as? YourCustomTableViewCell, let isExpanded = _expandedCells[indexPath] else { return }
   
       cell.set(expanded: isExpanded)
   }